The gonadotropins: Tissue-specific angiogenic factors?

Reisinger, Kerstin; Baal, Nelli; McKinnon, Timothy; Münstedt, Karsten; Zygmunt, Marek

doi:10.1016/j.mce.2006.11.015

Cited by 66 publications

(49 citation statements)

References 226 publications

(169 reference statements)

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Accordingly, testicular germ cells of several species express KDR and FLT1 (Ergun et al 1997, Nalbandian et al 2003, Rudolfsson et al 2004, and although these receptors are expressed in endothelial cells, no active angiogenesis takes place within the postnatal testis. VEGF synthesis by Leydig cells is stimulated in response to hCG/LH (Rudolfsson et al 2004), and FSH triggers Sertoli cell production of VEGF in the adult testis (Marti & Risau 1998, Liu & Yang 2004, Reisinger et al 2007. Interestingly, FSH has been shown to stimulate proliferation of spermatogonia (De Rooij et al 1989), and type A spermatogonia express KDR in neonatal mice (Nalbandian et al 2003).…”

Section: Discussionmentioning

confidence: 99%

Vascular endothelial growth factor regulates germ cell survival during establishment of spermatogenesis in the bovine testis

Caires

Avila²,

McLean

2009

Reproduction

View full text Add to dashboard Cite

Vascular endothelial growth factor-A (VEGFA) is a hypoxia-inducible peptide essential for angiogenesis and targets nonvascular cells in a variety of tissues and cell types. The objective of the current study was to determine the function of VEGF during testis development in bulls. We used an explant tissue culture and treatment approach to test the hypothesis that VEGFA-164 could regulate the biological activity of bovine germ cells. We demonstrate that VEGFA, KDR, and FLT1 proteins are expressed in germ and somatic cells in the bovine testis. Treatment of bovine testis tissue with VEGFA in vitro resulted in significantly more germ cells following 5 days of culture when compared with controls. Quantitative real-time RT-PCR analysis determined that VEGF treatment stimulated an intracellular response that prevents germ cell death in bovine testis tissue explants, as indicated by increased expression of BCL2 relative to BAX and decreased expression of BNIP3 at 3, 6, and 24 h during culture. Blocking VEGF activity in vitro using antisera against KDR and VEGF significantly reduced the number of germ cells in VEGF-treated testis tissue to control levels at 120 h. Testis grafting provided in vivo evidence that bovine testis tissue treated with VEGFA for 5 days in culture contained significantly more differentiating germ cells compared with controls. These findings support the conclusion that VEGF supports germ cell survival and sperm production in bulls.

show abstract

Section: Discussionmentioning

confidence: 99%

Vascular endothelial growth factor regulates germ cell survival during establishment of spermatogenesis in the bovine testis

Caires

Avila²,

McLean

2009

Reproduction

View full text Add to dashboard Cite

show abstract

“…This rate could be increased by hCG stimulation of Leydig cells. In addition, hCG influenced testicular blood flow, and increased vascular permeability in rat testis [3].…”

Section: Open Accessmentioning

confidence: 92%

“…VEGF is also known as Vascular Permeability Factor (VPF) with an effect 50,000 times higher than histamine [3]. It is well known that Leydig cells secrete VEGF and its receptors, VEGFR 1 and 2 are expressed on blood vessel [2,5].…”

Section: Open Accessmentioning

confidence: 99%

Morphologic changes due to human chorionic gonadotropin in the rat testis: Role of vascular endothelial growth factor

Papparella¹,

Nino²,

Noviello³

et al. 2013

OJPed

View full text Add to dashboard Cite

Introduction: Human chorionic gonadotropin (hCG) has an important role in the regulation of reproductive system and a high capacity to stimulate angiogenesis by secretion of vascular endothelial growth factor (VEGF). It could be also used for medical treatment of cryptorchidism, as it stimulates Leydig cells to produce testosterone, but its use has been discussed. Aim of the study was to evaluate the testicular morphological changes due to cyclic administration of hCG possibly related to VEGF effect. Methods: 80 pre-puberal male Sprague-Dawley rats were randomly divided in two groups hCG (50 U/I/ Kg) (n = 55/S) and placebo (n = 25/C) treated. The animals were sacrificed respectively after one (S1 n = 10; C1 n = 5), two (S2 n = 10; C2 n = 5) and three weeks of hCG or placebo treatment (S3 n = 35; C3 n = 15); a blood serum was obtained for evaluation of plasmatic testosterone. The testis, prostates, epididymides and seminal vesicles were drawn and weighted. Specimens were fixed in formalin and coloured by hematoxylin-eosin. Morphometric analysis of Leydig cell number, nuclear area and perimeter was carried out. Immunoistochemistry for VEGF has been performed with the avidin-biotin peroxidase technique. Statistical differences between groups, each of different age, were calculating using Student's T-test. Results: After the first week of hCG treatment it has been observed an increased testicular weight and volume (+/−6%) in experimental respect to control group. This result was not observed after the second and third week of treatment. Significant variations were also observed in the mean prostate weight, whereas mean seminal vesicles weight was significant in the S2 and S3 groups respect to control. In the hCG treated rats it has been observed a poor differentiation of the seminiferous epithelium, with high Leydig cell evidence and increased intertubular eosinophilic material. An interstitial edema was demonstrated without inflammatory cell changes. Morphometric analysis confirmed an increased number of Leydig cells that were always strongly immunostained for VEGF. Low-medium reactivity was present in spermatogonial, peritubular, endothelial and Sertoli cells. Testosterone plasmatic values showed a statistically significant and progressive increase. Conclusions: hCG treatment clutters the germinative line and modifies VEGF testicular expression, suggesting its role in male reproductive system. The increased number of Leydig cells and the immunostaining for VEGF suggests an intense interstitial and metabolic arrangement. The morphologic modifications induced by hCG treatment and its influence on testis function raise the question about its use in the medical treatment of cryptorchidism.

show abstract

“…Near ovulation, was shown that an extensive vascularity is formed in the follicular wall until the ovulation occurs (Geva & Jaffe 2000, Reisinger et al 2007). Subjective and objective methods are validated and can be used to measure follicular vascularity in cows and mares (Ginther et al 2007).…”

Section: Introductionmentioning

confidence: 99%

Follicle and corpus luteum size and vascularity as predictors of fertility at the time of artificial insemination and embryo transfer in beef cattle

et al. 2015

View full text Add to dashboard Cite

Abstract:Two ultrasound based fertility prediction methods were tested prior to embryo transfer (ET) and artificial insemination (AI) in cattle. Female bovines were submitted to estrous synchronization prior to ET and AI. Animals were scanned immediately before ET and AI procedure to target follicle and corpus luteum (CL) size and vascularity. In addition, inseminated animals were also scanned eleven days after insemination to target CL size and vascularity. All data was compared with fertility by using gestational diagnosis 35 days after ovulation. Prior to ET, CL vascularity showed a positive correlation with fertility, and no pregnancy occurred in animals with less than 40% of CL vascularity. Prior to AI and also eleven days after AI, no relationship with fertility was seen in all parameters analyzed (follicle and CL size and vascularity), and contrary, cows with CL vascularity greater than 70% exhibit lower fertility. In inseminated animals, follicle size and vascularity was positive related with CL size and vascularity, as shown by the presence of greater CL size and vascularity originated from follicle with also greater size and vascularity. This is the first time that ultrasound based fertility prediction methods were tested prior to ET and AI and showed an application in ET, but not in AI programs. Further studies are needed including hormone profile evaluation to improve conclusion.

show abstract

The gonadotropins: Tissue-specific angiogenic factors?

Cited by 66 publications

References 226 publications

Vascular endothelial growth factor regulates germ cell survival during establishment of spermatogenesis in the bovine testis

Vascular endothelial growth factor regulates germ cell survival during establishment of spermatogenesis in the bovine testis

Morphologic changes due to human chorionic gonadotropin in the rat testis: Role of vascular endothelial growth factor

Follicle and corpus luteum size and vascularity as predictors of fertility at the time of artificial insemination and embryo transfer in beef cattle

Contact Info

Product

Resources

About